I have enjoyed very much reading this paper. The paper asks a fundamental question in ecology and evolution: does the fast-slow continuum, which was hypothesised at the population level, also recapitulate itself at the individual level. The authors target this question by amalgamating a rather impressive volume of data across dozens of species, for which long-term, individual-level records can be calculated. The metrics of life history (e.g., get T, longevity, degree of reproduction, etc.) are then calculated at the species and individual level. The authors find a fast-slow continuum at the species level, but not at the individual level, showcasing that assumptions regarding the coupling of F-S and POL, historically held by behavioural ecologist, needs to be carefully treated and contextualised.

I have carefully annotated the document (I wish good luck to the authors deciphering my handwriting!; attached), but the main points that I'd suggest to improve on are:

• The PCA analyses of F-S continuum done at the individual/population level bypass phylogenetic corrections. These are in fact easy enough to do if one assumes that the individual/populations have "diverged" in an infinitesimal amount of time ago. My lab did this recently and the methods are presented here: https://www.biorxiv.org/content/10.1101/2021.09.29.462372v2. This might be useful to the authors. I'm happy to provide R code if the authors would like.

• Explanation to a non-expert reader re the broken-stick model is required.

• Discussion regarding the impact of treating recruitment different for birds than for mammals is also required.

• The assumption of the approach to collapse F-S traits from individual data to populations is that these are normally distributed (L. 173)... but are they? this needs to be shown.

• The claimed V shape (L 254) is too forced.

Overall, a very important piece of work for the discipline, but I'd suggest that it still could benefit from some further careful statistical treatment of how one upscales from individual life history trait to pop/species level traits.